NORMAN M. BRADBURN is senior vice president for National Opinion Research. He is the Tiffany and Margaret Blake Distinguished Service professor in the department of psychology and the Harris Graduate School of Public Policy Studies at the University of Chicago.

SEYMOUR SUDMAN is a Walter H. Stellner Distinguished Professor of Marketing and deputy director and research professor at the Survey Research Laboratory at the University of Illinois, Urbana-Champaign. He is the author, coauthor, or editor of seventeen books including Asking Questions (Jossey-Bass, 1982) which he wrote with Norman M. Bradburn.